Process and Apparatus for the Combustion and Evaporation of Radioactive Residues

1,163,099. Processing radio-active waste. EUROPEAN ATOMIC ENERGY COMMUNITY. 17 Feb., 1967 [18 Feb., 1966], No. 5733/67. Heading G6R. In a process for the combustion and evaporation of radioactive residues, heat released by combustion of radio-active residues is employed to evaporate other, liquid radio-active residues. An apparatus for use with this process comprises a burner 3 fed with liquid highboiler residues by a pump 2 from a tank 1 and with air from a blower 12. Preheating of the burner 3 is effected by means of heavy fuel oil fed into the burner 3 by a pump 7 from a tank 6. The burner 3 penetrates by means of an extension tube 14 into a postcombustion chamber 15 in which combustion initiated in the burner 3 is completed. The burner 3 preferably operates at a temperature of at least 1100‹ C. and the chamber 15 at a temperature of at least 900‹ C. During the preheating of the burner 3, the combustion gases from the chamber 15 are directed by a valve 17 into a heat exchanger 19 fed at the upper end by air from the blower 12. The heated air leaves at the lower end 21 to heat and evaporate the radio-active liquid in a vessel 18. The combustion gases leave the heat exchanger 19 at the upper end and are channelled to one or more smoke-purifiers 23 and/or one or more gas-scrubbers 24. The use of a heat exchanger is necessary to avoid pollution of the liquid to be evaporated. When the preheating of the burner 3 is completed and boiling of the liquid high-boiler residues commences, the combustion gases from the chamber 15 are fed directly into the vessel 18 by a valve 16. The radio-active concentrate leaves the vessel 18 by means of tubing 26 and the vapour by means of a separator 27 leading to a Raschig-ring column 29 and a cyclone 30. The condensate returns to the vessel 18 and the vapour leaves the column 29 at the upper end and enters a condenser 33. The condensate leaving the condenser 33 at the lower end enters, together with the non-condensable gases and vapours, a separator 35 from which the condensate is removed, the non-condensable gases and vapours passing through a gas-scrubber 24. The liquid high-boiler residues fed from the tank 1 may be those derived from the purification of an organic coolant or moderator liquid after use in a nuclear reactor.